1. Field of the Invention
The invention relates to a monitoring device of power line and camera, which ingrates single power line, signals, and power supply.
2. Description of the Related Art
When reversing a vehicle 80 as shown in FIG. 1, the driver must rely on the rearview mirror to detect objects in the rear of the vehicle 80; however, right behind the vehicle 80 is a dead space for detection.
The vehicle 80 such as the trailers, trucks has a tractor 801 to lead the container 802 so that it is not easy for drivers to detect objects surrounding the vehicle 80. Moreover, the tractor 801 and container 802 are separated because of transportation considerations, resulting difficult wiring of transmission lines of power or signal for a monitoring device.
With the referenced to FIG. 2, the U.S. Pat. No. 5,680,123 disclosed three video cameras 82 to detect objects in the regions A, B, and C, and a display apparatus (not shown) installed in the tractor 801 to show the objects from regions A, B, and C by signal control switch (not shown). However, it is hard to install signal transmission lines and power transmission lines of the monitoring device on the vehicle 80.
With the referenced to FIG. 3, the U.S. Pat. No. 6,995,687 disclosed a radio frequency transmission without wiring having an information provider 83 installed at the tractor 801, and a detector installed at the container 802 to transmit non-wired image signals S80, S83, S84. However, interference problem of wireless transmission easily occurs in the car.